Electronic circuits with high frequency signals on printed circuit boards are sometimes difficult and expensive to design and manufacture. This is due to the fact that high frequency signals carried on traces on the top of circuit boards often transmit electromagnetic interference that can disrupt the normal operation of the circuit.
One solution known in the art for reducing interference emanating from traces carrying high frequency signals is to manufacture circuit boards with high frequency traces isolated between two ground layers within the circuit board. Such a solution, however, can be unsuccessful because it typically requires sending the high frequency signal along a via to an inner board layer. The via may create more interference by acting as an antenna and transmitting electromagnetic interference through the circuit, especially if the via leaves an open stub. Open stubs can be eliminated by using blind vias and buried vias, but such solutions and additional circuit board manufacturing steps and increase manufacturing costs significantly.
Another solution in the art for manufacturing circuit boards with high frequency signals is to use circuit boards made from special dielectric materials configured to suppress electromagnetic interference. A shortcoming of this solution is that it generally adds substantial manufacturing costs to the circuit. Using expensive circuit board material is especially unfavorable when there are only a small number of high frequency signals radiating electromagnetic interference through the circuit.